Laem Sadet-Kung Graben Harbor

Laem Sadet is the sandy cape that separates Ao Khung Krabaen bay from Hat Chao Lao beach, about 25 km from Tha Mai district town in Chanthaburi. On the bay side, a sheltered cove of pale gold sand curves beneath casuarina trees — calm enough for swimming most of the year, and shallow enough that low tide pulls the water well back from the treeline. It’s a working stretch of coast as much as a beach: small fishing boats work the bay, and a scatter of seafood grills sets up along the sand selling the day’s catch.

Casuarina shade runs the length of the beach, with vendor stalls grilling prawns, squid, corn, and sweet potato under the trees — cheap, fresh, and cooked to order rather than pre-made. A free aquarium sits just back from the beach, run alongside the Kung Krabaen Bay Royal Development Study Center a short walk inland: dozens of tanks of local reef and estuary fish, a walk-through fish tunnel, and information boards on the bay’s marine life — a good rainy-day fallback or a way to fill half an hour either side of the beach. Locals treat Laem Sadet as a picnic and paddling spot rather than a resort beach: expect Thai families with mats and coolers rather than sun loungers.

Weekdays are close to empty; weekends bring day-trippers from Chanthaburi and Rayong, still a fraction of the crowds at Thailand’s headline beaches. The bay’s calm water also supports mangrove kayak trips run out of the Study Center — worth booking ahead if you want to see the mangrove fringe from the water rather than the boardwalk.

Insider Tip: Time a visit to low-to-mid tide — at full high tide the sand strip narrows considerably and the grill vendors lose their usual pitch.

Watch out: Shade thins out toward midday and there’s no real infrastructure beyond the food stalls — bring your own water, and don’t expect showers or changing rooms.

Pair Laem Sadet with the Study Center’s mangrove boardwalk and the Laem Sadet Arboretum next door for a full half-day loop of this stretch of the Chanthaburi coast — all three sit within a few minutes’ drive of each other in Tha Mai district.